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Discussion Starter #1
We just added a 2005 ext cab to the towin fleet. It is a dually. It has the LLY.

We just took a 340 mile rode trip towing a trailer and only got 10mpg towing.:help

The truck is bone stock, and has the auto tranny.

Ive read to upgrade the turbo mouthpiece. Where do I find one?

I would guess atleast a 4 inch if not a 5 inch exhaust.

Then a programmer? We have good luck with the edge attuide on a dodge.

This truck is going to make the 340 journey weekly if not twice a week.

What are you guys running and what mpg your getting.

Thanks :drink
 

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576 Posts
When my girl was stock, I got 12 towing my 5er. Have yet to do a decent trip with all the new mods
 

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I only get about nine towing my enclosed trailer.
 

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How heavy was the load? How many gallons do you carry 26 or bigger? I hauled 32'gn with 8k forklift and 2k of metal and got low 9's.
 

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Discussion Starter #7
We dont have a transfer tank on this rig. Just the factory fuel cell. We are pulling around 4 ton.

The trailer we are pulling is a bumper pull. Will a goose neck trailer help mpgs?
 

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I pull an enclosed trailer(2200lbs) loaded with(4800lbs) of product every day. My daily route is around 120 miles in length and over the last month I am averaging 12.7 miles per gallon. I added a predator economy tune to my 2004 ext cab 4x4 running on 33's and now I get around 14.5 if I drive normal.
 

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For me the weight is not such a big issue as the wind resistance.
A enclosed trailer with the same weight as a flat deck will get worse milage. A V nose trailer helps to reduse wind drag.
Areodynamics is important look at the semis on the road. Lower hoods and wind deflectors on the sleeper.
 

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I got 14 mpg towing 7k, a pickup on a car trailer last Thursday. 300 mile trip doing 72mph average highway with heavy traffic through the cities. Stop and go for about an hour.

City mileage weight is the determining factor,
Highway wind resistance is.
 

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I got 11 Mpg Towing 8K - Enclosed trailer full of toys, truck full of boys- off to the dunes. Mountain roads included, 70-80 Mph. I also had my FOOT IN IT.
Edge Evo Lvl 2.
Hand Calculated.
 

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I get about 10 to 11 as well when towing my toy hauler, about 11,000 lbs when fully loaded. Worst I got was 6 mpg when driving in a very windy day, 40 mph winds. Wont do that again.
 

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A mechanic I know says to increase mileage do these steps
he does cutom mods to trucks.
Ranked as importance. Exhaust, intake and then programmer.
 

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The IOH kit will do more for LLY towing economy than any other change. Tuning second. True CAI third. Exhaust 4th
 

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An lly at work gets about 15 to 16 towing heavier loads it has 4 inch, banks intake, afe mouthpiece, afe cai tube, fitch fuel catalyst and a 50 hp efi tow tune
 

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Change fuel filter, believe it or not it helps. Driver habits are next biggy. Winter fuel/summer fuel? What trailer/weight are you pulling? DId you check tire presser of all tires and max out?
 
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